I have just a couple suggestions to simplify locating friends and guild members in town, and determining when they log in/out.
Make guild member names appear in a different color when in town - for example, when holding down ctrl in a town, the names of members of your guild will appear as light orange instead being lost in the mass of blue
Have friends names show up similar to the description above, but in a different color
Be able to set an alert on a guild member/friend so you receive an audio and/or chat window message when that person comes online
Good idea folks. What I would also like to see is the professions of your guild members when you roll your mouse over their current logged on character in the guild window.